The actual stolen plane videoed by onlookers before it crashed near Seattle after a chase by F15 fighter jets. @drbmbdgty

A “suicidal” airline mechanic stole an Alaska Airlines plane without any passengers on it, took off from Washington state, and crashed near an island.

The mechanic commandeered the Horizon Air Q400 aircraft from Seattle-Tacoma International Airport, and the crash occurred because he was “doing stunts in [the] air or [a] lack of flying skills”, the sheriff’s department said on Twitter on Friday.

The plane was chased by military F-15 aircraft but was reportedly not involved in the crash near Ketron Island, southwest of Tacoma.

The man could be heard on audio recordings telling air traffic controllers he is “just a broken guy”.

Witnesses reported seeing the plane being chased by military aircraft near the airport.

Officials said the 29-year-old man who stole the plane was “suicidal” and there is no connection to terrorism.

Seattle-Tacoma officials said the airline employee had “conducted an unauthorised takeoff without passengers”.

Pierce County Sheriff Paul Pastor told KIRO7 news station in Seattle the pilot appeared to have acted alone and was likely killed in the crash.

Witness Royal King told The Seattle Times he was photographing a wedding when he saw the low-flying turboprop being chased by two F-15s. He said he didn’t see the crash but saw smoke.

“It was unfathomable, it was something out of a movie,” King said. “The smoke lingered. You could still hear the F-15s, which were flying low.”

The US Coast Guard was sending a vessel to the crash scene.

Horizon Air is part of Alaska Air Group and flies shorter routes throughout the US west. The Q400 is a turboprop aircraft with 76 seats.

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